Slimline

Sony's 8.1-megapixel DSC-T70 cyber-shot is essentially a scaled-down version of the T200 model with a marginally smaller, lighter body, shorter zoom range and smaller LCD. Unlike previous T-series models, both are controlled via touch screens, which cover the rear panel and they are so similar in the functions they offer that they share the same user handbook. The T70 is $150 cheaper.

Body design is typical of the T-series, with a slide-down lens cover that doubles as an on/off switch. The only button controls are on the top panel, covering power, playback shutter release and zoom rocker. All of them are so small you need a fingertip to use them and our seven-year-old ease-of-use assessor even had difficulties with the zoom rocker, which is particularly tiny.


Front view with the slidning lens cover/on-switch panel down.


Top panel buttons.

The touch-panel interface was introduced almost two years ago with the N1 model and Sony has adapted it to present its updated menu interface in the new T-series cameras. It's fairly straightforward, although you often have to tap several times on a 'button' to get it to work. The control suite is typical of most point-and-shoot digicams and provides an adequate range of resolution settings (but no compression adjustments), metering and focus modes but the white balance menu lacks a custom measurement setting.


Rear panel.

Manufactured in silver, black and pale pink, the T70 sports the latest Bionz image processor, which promises fast response times and low noise at high sensitivity settings and supports face detection and dynamic range optimisation. The face detection function is hidden away in the shooting menu and only usable with the Auto and the Smile Shutter and Soft Snap Scene modes. Two settings are provided: continuous and when touched, the latter focusing only when the screen is touched (and you don't need to touch the subject's face). The system can detect up to eight faces – but only four in Soft Snap mode.

We found the Smile shutter mode (which replaces the traditional Portrait setting) quite frustrating to use as the shutter will only fire when a smile is detected. We had several false positives when the detection level was set to High but, with the Low setting, the camera would only fire when a broad grin (with lots of visible teeth) was detected. Even slight backlighting tended to reduce detection accuracy and with subjects wearing glasses it was a hit-and-miss exercise. On the whole, we found it easier to take portrait shots without this function.

When face detection is activated, the flash will automatically provide two or three pre-flashes to reduce red-eyes. Red-eye reduction pre-flash can also be engaged when shooting in Program AE mode via the camera's menu. In Program AE mode you can select one of five Colour Mode settings: Normal (the default), Vivid, Natural (for slightly subdued saturation), Sepia and B&W. Flash output is also adjustable – but only in Program AE mode.

Two digital zoom settings are provided: Smart Zoom and Precision Zoom. The former enlarges the image digitally within a pre-set range that varies with the camera's resolution with up to 3.8x enlargement possible at the 5M setting and 15x with VGA resolution. Precision Zoom enlarges all image sizes up to a maximum of 6x. Digital Zoom is not usable when the camera is set for face detection.

Long exposures are not possible with the T70, which has a maximum exposure of one second, even with the Twilight and Fireworks modes. As well as the Auto setting, the T70 provides six white balance pre-sets, three of them covering fluorescent lighting. No manual measurement is available and you can't fine-tune flash settings or apply flash bracketing to overcome the limitations of the system (outlined in the Performance section below).

The T70 records still images as JPEGs and video clips as MPEG1 files. Interestingly, while you can record still shots in 16:9 format with a resolution that's ideal for displaying on an HDTV screen, you can only capture video clips with 4:3 aspect ratio. Given the T70's wider-than-average LCD screen, this anomaly is difficult to explain.

No facility is provided for adjusting image compression ratios which, fortunately, aren't quite as high as they were in the T100, which has the same sensor resolution. Typical still image sizes are shown in the table below.

Movie settings are equally limited, with only two resolutions: VGA and QVGA and three frame rates. No provision is made for shooting video clips at 160 x 120 pixels for emailing. Video sizes, frame rates and recording times are shown in the table below.

Playback facilities are pretty standard and include index and slideshow playback, protect and delete functions, DPOF marking for automated printing, rotation and some interesting in-camera editing facilities. Slideshows can be played back with a range of effects (Simple, Nostalgic, Stylish, Active and Normal) and any of four pre-loaded background music clips (Simple, Nostalgic, Stylish and Active). You can upload your own background music to the camera with the Music Tool in the Printing menu.

In-camera retouching functions include Soft Focus, Partial Colour, Fisheye Lens, Cross Filter, Trimming, Red-eye Correction, Radial Blur and Retro, the latter softening the image to create the effect of an old photograph. You can also 'paint' characters or graphics on still images, a function introduced with Sony's first touch-screen digicam. During playback it is also possible to change the aspect ratio of shots and display images shot in 4:3 or 3:2 aspect ratio in widescreen 16:9 format.

Performance
Pictures taken with the test camera were bright and colourful with plenty of detail and lively colours. Exposures were biased slightly in favour of shadows so highlights tended to block up in outdoor shots, although dynamic range was wider than we've found in many digicams. (This is probably due to the Bionz image processor.)

Imatest showed the test camera's resolution to be slightly below expectations for an 8-megapixel digicam and revealed slight edge softening plus a small degree of barrel distortion at wider angles of view. No distortion was obvious at the tele end of the zoom range. Resolution began to decline at ISO 800 and was very low at ISO 3200, where noise was also obvious.

Lateral chromatic aberration was severe throughout the zoom range, and coloured fringes were evident both at the edges and towards the centre of shots taken in bright outdoor lighting. Imatest showed colour accuracy to be generally good, although saturation was elevated in the red sector of the spectrum and we observed slight shifts in skin hues and purplish blues.


Coloured fringes at the edge of a test shot.


Coloured fringes towards the centre of the same shots as above.

The flash required ISO 800 to illuminate an average-sized room but delivered good results with close-ups. Image noise became visible at ISO 800, although you would still be able to print shots taken at this setting at snapshot size. Noise was very obvious at ISO 33200, where shots looked blotchy and unsharp. Close-up performance was good and the Magnifying Glass mode provided some excellent ultra-close pictures. Digital zoom shots taken with the camera set at its highest resolution were crisp and clean and relatively free of processing artefacts.

The test camera powered up in just over 1.5 seconds and we measured an average capture lag of 0.4 seconds, which reduced to less than 0.05 seconds with pre-focusing. It took approximately 2.2 seconds to process each shot and shot-to-shot times averaged three seconds. In the continuous shooting mode, the test camera recorded shots at two frames/second. It took 6.7 seconds to process a burst of 20 shots. 

IMATEST GRAPHS

Resolution at low ISO settings.


Resolution at ISO 3200.

SAMPLE IMAGES

Auto white balance with incandescent lighting.


Auto white balance with fluorescent lighting.


Close-up.


Magnifying Glass mode.


Digital zoom.


ISO 80


ISO 3200

Image sensor: 5.76 x 4.29mm Super HAD CCD with 8.286 million photosites (8.1-megapixels effective)
Lens: Carl Zeiss Vario-Tessar 6.33-19.0mm f/3.5-4.3 zoom (38-114mm in 35mm format)
Zoom ratio:  3x optical, up to 6x digital
Image formats: Stills – JPEG (Exif 2.21); Movies – MPEG1
Image Sizes: Stills – 3264 x 2448, 3264 x 2176 (3:2), 2048 x 1536, 1920 x 1080 (16:9), 640 x 480: Movies – VGA at 30/16.6 fps; QVGA at 8.3 fps; QQVGA at 8.3 fps
Shutter speed range:  1-1/2000 second
Image Stabilisation: Optical (Super Steady Shot)
Face Detection: Yes: touch /continuous
Exposure Compensation: +/- 2.0EV, 1/3EV steps
Focus system/range: Single, Monitoring AF; range 50 cm to infinity; macro to 8cm; magnifying glass mode 1-20cm
Exposure metering/control: Multi Pattern, Centre Weighted, Spot metering; Program AE plus 8 scene presets
ISO range: Auto, ISO  80, 100, 200, 400, 800, 1600, 3200
White balance: Auto, Daylight, Cloudy, Fluorescent (x 3), Incandescent, Flash  
Flash modes/range (ISO auto): Auto, Forced-Flash, Slow Synchro, No Flash; range 0.1-3.0 metres
Sequence shooting:  100 shots at 2 fps (all resolutions)
Storage Media: 31MB internal memory plus Memory Stick Duo expansion slot
Viewfinder: n.a.
LCD monitor: 3.0-inch TFT LCD
Power supply:  NP-BD1 rechargeable lithium-ion battery (C.I.P.A rated for 270 shots/charge)
Dimensions (wxhxd): 90 x 56.4 x 20.7 mm
Weight: 128 grams (without battery and card)